1: Field of the invention
The present invention relates to the generation of electrical power, preferably using large hydro-turbines submerged in powerful ocean currents, but it may be adapted to tidal or weaker current applications.
2: Description of the Prior Art
There is an increasing need for greater amounts of electrical power, and an increasing desire to minimize pollution of the environment caused by generating the electrical power. Consequently, several imaginative techniques have been devised for harvesting power from the large-scale motions of seawater. E.g., the Gulf Stream along Florida's east coast transfers approximately 517 gigawatts of power northward, or about 4.5 petawatt/hours each and every year. Ocean currents are driven by heat differentials on the earth due to uneven insolation. The present invention addresses the difficulty in extracting usable portions of this low-density power in an economical way.
U.S. Pat. No. 868,798, issued on Oct. 22, 1907, to Robert McLaughlin, discloses a means for obtaining power from flowing water, including a screw propeller and a dynamo.
U.S. Pat. No. 1,123,491, issued on Jan. 5, 1915, to Elbert A. Corbin, discloses a power conversion plant for converting the energy in water currents into electricity, including a turbine and generator.
U.S. Pat. No. 2,730,631, issued on Jan. 10, 1956, to Juliana S. Dandini, discloses a water current-driven motor including a generator.
U.S. Pat. No. 3,209,156, issued on Sep. 28, 1965, to Arthur D. Struble, Jr., discloses an impeller driven underwater generator for converting the force of subsurface water currents into electrical energy. The instant invention is distinguishable, in that it includes two separate sets of rotor and stator coils, between which current is transmitted.
U.S. Pat. No. 3,604,942, issued on Sep. 14, 1971, to Curtis A. Nelson, discloses an underwater generator, having radially extending arms, each arm pivotally carrying a paddle that can both open and close against water current.
U.S. Pat. No. 3,912,937, issued on Oct. 14, 1975, to Jerome M. Lesser, discloses a submarine electrical energy generating apparatus, having a turbine with pivoting louvers. The instant invention is distinguishable, in that it includes two separate sets of rotor and stator coils, between which current is transmitted.
U.S. Pat. No. 3,928,771, issued on Dec. 23, 1975, to O. Robert Straumsnes, discloses a water current power generator system, including a ship anchored to the bottom, having an inlet and an outlet for water. The instant invention is distinguishable, in that it does not require the constant presence of a ship to generate electricity.
U.S. Pat. No. 4,026,587, issued on May 31, 1977, to Robert H. Hultman and Dennis C. Hultman, discloses an underwater turbine operated by ocean currents, with propeller blades outside a housing and a generator inside the housing.
U.S. Pat. No. 4,256,970, issued on Mar. 17, 1981, to Osvaldo Tomassini, discloses an apparatus for the exploitation of underwater currents for the production of electrical energy, in which a water driven rotor turns when current flows, causing gears to turn, that cause a shaft in a generator to turn. The instant invention is distinguishable, in that it does not require drive means such as gears between the rotor and generator.
U.S. Pat. No. 4,306,157, issued on Dec. 15, 1981, to Lazar J. Wracsaricht, discloses an underwater slow current turbo generator, having blades extending from a shaft in a spiral pattern, with a cylindrical housing surrounding the blades. The generator may be near and around the shaft, or alternatively in the cylindrical housing (column 7, lines 24-26). The instant invention is distinguishable, in that it includes two separate sets of rotor and stator coils, between which electric current is transmitted.
U.S. Pat. No. 4,335,319, issued on Jun. 15, 1982, to John H. Mettersheimer, Jr., discloses a hydro-electric power apparatus utilizing ocean currents, with a power house and crew housing at the surface, which is not required by the instant invention.
U.S. Pat. No. 4,464,080, issued on Aug. 7, 1984, to Alexander M. Gorlov, discloses a high volume tidal or current flow harnessing system, including a dam not required in the instant invention.
U.S. Pat. No. 4,520,273, issued on May 28, 1985, to Raymond A. Rowe, discloses a fluid responsive rotor generator, that can be placed on the bottom of the ocean to generate electricity from current flow. Magnets may be placed on the rotor blades, or the blades may themselves be magnetized. Wires are mounted on the framework about the rotor, so that electricity will be generated when the rotor turns. The instant invention is distinguishable, in that it includes two separate sets of rotor and stator coils, between which electric current is transmitted.
U.S. Pat. No. 4,524,285, issued on Jun. 18, 1985, to Hans G. Rauch, discloses a hydro-current energy converter, which can be mounted on a platform resting on the sea bed, to generate electricity from ocean currents. A current-driven rotor turns a shaft that turns a generator. The instant invention is distinguishable, in that its rotor is itself part of the generator.
U.S. Pat. No. 4,720,640, issued on Jan. 19, 1988, to Bjorn M. S. Anderson and Reinhold H. Ziegler, discloses a fluid powered electrical generator, with an impellor-rotor having blades connected at their outward ends by a ring containing the rotor element of a generator, surrounded by a ring-shaped (toroidal) outside support structure containing the stator element of a generator. The instant invention is distinguishable, in that it has two separate sets of rotor and stator elements between which current is transmitted.
U.S. Pat. No. 5,230,215, issued on Jul. 27, 1993, to Tsugio Nagata, discloses an ocean current power generation system, having cup-like current-receiving members that hang from a horizontal ring.
U.S. Pat. No. 5,440,176, issued on Aug. 8, 1995, to Michael L. Haining, discloses ocean current power generators supported on a tension leg platform not required by the instant invention.
U.S. Pat. No. 6,006,518, issued on Dec. 28, 1999, to Jeffrey B. Geary, discloses an ocean current energy converter, including a rotating canister with pivotal fins.
U.S. Pat. No. 6,472,768, issued on Oct. 29, 2002, to Darwin Aldis Sails, discloses a hydrokinetic generator, having a scoop-like structure that funnels water into a turbine.
Japanese Patent No. 52-29547, published on Mar. 5, 1977, inventor Yoshitaro Ikeda, discloses a power generator using sea current that constantly flows in a definite direction.
Japanese Patent No. 55-69768, published on May 26, 1980, inventor Taiji Kaiho, discloses two rotor type water turbines that are placed left and right and coaxially, that are anchored to the sea bottom, but suspended like kites in the water.
Japanese Patent No. 56-77565, published on Jun. 25, 1981, inventor Shizukiyo Kawasaki, discloses a tubular ocean current power generating system utilizing bottom current.
British Patent No. 2 104 974, published on Mar. 16, 1983, inventor David Meir Slonim, discloses a wave and current energy converter, including a bucket wheel or bucket chain.
German Patent No. 39 24 673, published on Feb. 14, 1991, inventor Dr. Matthias Kratofiel, discloses a generator driven by an impeller mounted in a sea bed housing that can swivel and has fins that align it with the flow of water.
British Patent No. 2 256 011, published on Nov. 25, 1992, inventor Peter Leonard Fraenkel, discloses a floating water current turbine system.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.